Lightweight fluid carrying tanks have many applications. For example, the military will frequently have need for a transportable fluid carrying tank that can be moved to a forward position in combat. Such tanks can hold water, gasoline, diesel fuel, jet fuel, heating oil, drinking water, transformer oil, or any other fluid desired, as long as the material of the tank is resistant to the particular fluid carried. While such tanks can come in almost any size, common sizes are 150, 250 and 500 U.S. gallons.
One advantage of such lightweight fluid tanks is their ready portability. Tanks can be mounted on the bed of a truck, on various sizes of trailers, used directly on the ground, usually without stabilizing aids, etc. It is desirable for such a tank to be so well constructed that it can be lifted off a surface when full without using special equipment, such as nets, harnesses, pallets or boxes to reinforce the tank. Further, such tanks should be capable of being secured in a particular position to prevent the tanks from moving when on a vehicle, or the like.
While prior tank designs have proven generally satisfactory, particularly the so-called pillow tank design formed of a tube of material closed at each end to resemble a pillow, there exists a need for improved tank designs which achieve the objectives set forth above, while remaining lightweight, inexpensive to manufacture and use, yet be reliable.